Land

“… we have estimated the total EGS resource base to be more than 13 million exajoules (EJ). Using reasonable assumptions regarding how heat would be mined from stimulated EGS reservoirs, we also estimated the extractable portion to exceed 200,000 EJ or about 2,000 times the annual consumption of primary energy in the United States in 2005. With technology improvements, the economically extractable amount of useful energy could increase by a factor of 10 or more, thus making EGS sustainable for centuries.” Read the entire MIT report: The Future of Geothermal Energy (November 2006) here:

Exajoules are actually a pretty useful energy measure. 1 Exajoule is about 278 TWh. Earth always needs a steady flow of something between 12 and 18 TW of energy from all sources. Estimates vary from source to source but are always within this range. 1 TW = 1 (24) (365) = 8760 TWh

So the planet needs something like 15 x 8760 = 130,000 TWh of energy from all sources annually or about 470 Exajoules. Nice small numbers because EJ is a very big unit.

Does this agree with 200,000 EJ being 2000 times the annual consumption of primary energy in the US in 2005?

Primary energy consumption was about 27,000 TWh for the US in 2005 which is about 97 EJ.

So, yes, 200,000 EJ is about 2000 times the annual consumption of primary energy in the US in 2005.

The US can access 200,000 EJ of geothermal energy using Enhanced Geothermal Systems and we need 100 EJ of energy from all sources per year. EGS will last a while!

June 8, 2012. As reported by Renewable Energy World, “A new report from the Renewable Energy Association (REA) says the UK could meet a fifth of its power needs with geothermal energy, according to the Guardian. Geothermal could supply 9.5 GW of electricity, about 20 percent of current demand. It could also supply 100 percent of the UK’s space heating needs with about 100 GW of heat.” Read the complete article at

“Norway – There is a solution for the world’s insatiable energy needs. It is CO2-free and safe. And it’s located right under our feet.

Ever since Jules Verne wrote in 1864 about a trip to the Earth’s interior, people have dreamed of bringing up heat from the centre of the planet. So far we have only scratched the surface, but researchers are now beginning to work down into the depths.

The fact is that 99 percent of the planet has a temperature above 1000°C. The heat is what’s left over from when the Earth was first formed, and there is more than enough of it for us to transform it into energy.

“If we can drill and recover just a fraction of the geothermal heat that exists, there will be enough to supply the entire planet with energy – energy that is clean and safe,” says Are Lund, senior researcher at SINTEF Materials and Chemistry.” Read the entire article at